The present invention relates to new photoactive polymers, their use as liquid crystal (LC) orientation layers and their use in the construction of unstructured and structured optical and electro-optical elements and multi-layer systems.
The successful functioning of a Liquid Crystal Device relies upon the ability of the IC molecules within that device to assume and maintain an alignment imposed upon them. Alignment of the LC molecules is achieved by use of an orientation layer which defines a direction of orientation for the LC molecules of the device with the result that the longitudinal axes of the molecules become aligned with the direction of orientation defined by the orientation layer. In addition to this directional alignment, the orientation layer is also able to impart to the LC molecules an angle of tilt so that the molecules align themselves at an angle to the surface of the orientation layer rather than lying parallel thereto.
Tilt angles of between 1xc2x0 and 15xc2x0 are usual for Nematic LCDs. Tilt angles of about 7xc2x0 are required for supertwisted nematic (STN) LCDs in order to avoid the formation of so-called fingerprint textures. Vertically aligned nematic (VAN) LCD""s for instance require pretilt angles of between 85xc2x0 and 90xc2x0.
Methods of preparing structured and unstructured orientation layers are well known to a skilled person. In particular it is known that by using linearly polarised light it is possible to prepare orientation layers in which both the direction of orientation and the tilt angle of the orientation layer are determined by the direction and angle of incidence of the plane polarised light used to irradiate said layer.
Structured orientation layers are of great interest in many areas of display technology and integrated optics. These layers are characterised by regions (pixels) which alternate in respect of the direction of orientation and angle of tilt of their component molecules. These orientation layers can be used to improve the viewing angle dependency of TN, STN and VAN LCDs, for example:
A possible method of producing high-resolution structured orientation patterns in liquid crystalline layers is described in Jpn. J. Appl. Phys., Vol. 31 (1992), 2155. In that process the dimerisation of polymer-bonded photoreactive cinnamic acid groups induced by irradiation with linearly polarised light is employed for the structured orientation of liquid crystals. Those photo-oriented polymer networks can be used wherever structured or unstructured liquid crystal orientation layers are required. In addition to their use in LCDs, these orientation layers can also be used, for example, in the production of so-called hybrid layers, as illustrated in European Patent Applications EP-A-0 611 981, EP-A-0 689 084 and EP-A-0 689 065. It is possible, using these hybrid layers of photostructured orientation polymers and crosslinkable low molecular weight liquid crystals to prepare optical elements such as, non-absorptive colour filters, linear and circular polarisers, optical delay layers and so on.
The ability of the resulting orientation layers to perform their function thus depends, in part, upon the number of molecules in the layer that have been dimerised as a result of irradiation with linearly polarised light. The extent to which the molecules are dimerised relies, in part, on the irradiation time, the irradiation energy and the structure of the molecules being irradiated.
EP-A-0 611 786, EP-A-0 763 552, EP-A-0 860 455, WO 96/10049 and WO 99/15576 describe polymers that are suitable in principle for the production of such anisotropically crosslinked, photostructured orientation layers for liquid crystals.
However, a problem with many polymers currently used in the preparation of photo-orientated orientation layers is that relatively long irradiation times are required to effect efficient dimerisation of the component molecules. There is, therefore, a need for photo crosslinkable polymers that can be readily cross-linked over a relatively short irradiation time. The present invention addresses that need.
A first aspect of the present invention provides a polymeric compound comprising a repeating unit of formula (I) 
in which:
A represents a nitrogen atom, a carbon atom, a group xe2x80x94CR1xe2x80x94 or an aromatic or alicyclic group, which is optionally substituted by a group selected from fluorine, chlorine, cyano and a C1-18 cyclic, straight-chain or branched alkyl group, which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Si(CH3)2xe2x80x94Oxe2x80x94Si(CH3)2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94O, xe2x80x94Oxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94, wherein R1 represents a hydrogen atom or lower alkyl,
M represents a repeating monomer unit;
n1 to n3 each independently represent 0 or an integer having a value of from 1 to 3, with the proviso that 1 less than n1+n2+n3 less than 4;
P1, P2, P3 each independently represents a photoactive group; and
B1 to B4 each independently represent a residue of general formula II 
in which
S1 to S3 each independently represent a single bond or a spacer group selected from a C1-24 straight-chain or branched alkylene group, which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent alkylene xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Si(CH3)2xe2x80x94Oxe2x80x94Si(CH3)2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94 wherein R1 is as defined above,
C1 and C2 each independently represents an aromatic or an alicyclic group, which is optionally substituted by a group selected from fluorine, chlorine, cyano or a C1-18 cyclic, straight-chain or branched alkyl group, which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Si(CH3)2xe2x80x94Oxe2x80x94Si(CH3)2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94 wherein R1 represents a hydrogen atom or lower alkyl, and
n4 and n5 are each independently 0 or 1.
The polymeric compounds of the present invention can be readily aligned upon exposure to linearly polarised light. In addition, by using the compounds of the invention, it is possible to reduce the irradiation time required to form cross-linked polymer films.
By the term xe2x80x9caromaticxe2x80x9d it should be understood to include optionally substituted carbocylic and heterocyclic groups.
By the term xe2x80x9ccyclic, straight-chain or branched alkyl group, which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94 and xe2x80x94Cxe2x89xa1Cxe2x80x94,xe2x80x9d it should be understood to include groups selected from the group comprising methyl, ethyl propyl, isopropyl, butyl, isobutyl, sec-butyl tert-butyl pentyl, isopentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl 3-methylpentyl, allyl, but-3-en-1-yl, pent-4-en-1-yl, hex-5-en-1-yl, propynyl, butynyl, pentynyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy, isopentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, 3-methylpentyloxy, allyloxy, but-3-enyloxy, pent-4-enyloxy, cylohexylmethoxy, cyclopentylmethoxy, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, tert-butoxycarbonyl, pentyloxycarbonyl, isopentyloxycarbonyl, cyclopentyloxycarbonyl, hexyloxycarbonyl, cyclohexyloxy, carbonyl, octyloxycarbonyl, nonyloxycarbonyl, decyloxycarbonyl, undecyloxycarbonyl, dodecyloxycarbonyl, 3-methylpentyloxycarbonyl, allyloxycarbonyl, but-3-enyloxycarbonyl, pent-4-enyloxycarbonyl, cylohexylmethoxycarbonyl, cyclopentylmethoxycarbonyl, acetoxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, pentylcarbonyloxy, isopentylcarbonyloxy, cyclopentylcarbonyloxy, hexylcarbonyloxy, cyclohexylcarbonyloxy, octylcarbonyloxy, nonylcarbonyloxy, decylcarbonyloxy, undecylcarbonyloxy, dodecylcarbonyloxy, 3-methylpentylcarbonyloxy, but-3-enyloxy, pent-4-enyloxy, acetyl, ethylcarbonyl, propylcarbonyl, isopropylcarbonyl, butylcarbonyl, isobutylcarbonyl, sec-butyl-carbonyl, pentylcarbonyl, isopentylcarbonyl, cyclohexylcarbonyl, octylcarbonyl, nonylcarbonyl, decylcarbonyl, undecylcarbonyl, dodecylcarbonyl, methoxyacetoxy, 1-methoxy-2-propoxy, 3-methoxy-1-propoxy, 2-methoxyethoxy, 2-isopropoxyethoxy, 1-ethoxy-3-pentyloxy, 3-butynyloxy, 4-pentynyloxy, 5-chloropentynyl, 4-pentynecarbonyloxy, 6-propyloxyhexyl, 6-propyloxyhexyloxy, 2-fluoroethyl, trifuoromethyl, 2,2,2-trifuoroethyl, 1H,1H-pentadecafluorooctyl, 1H,1H,7H-dodecafluoroheptyl, 2-(perfluorooctyl)ethyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorodecyl)ethyl, perfluoropropyl, perfluorobutyl, perfluoroheptyl, perluorooctyl, perfluorononyl, 1-fluoropropoxy, 1-fluoropentyloxy, 2-fluoropropoxy, 2,2-difluoropropoxy, 3-fluoropropoxy, 3,3-difluoropropoxy, 3,3,3-trifluoropropoxy, trifluoromethoxy and the like.
By the term xe2x80x9clower alkylxe2x80x9d it should be understood to include straight chain and branched hydrocarbon radicals having from 1 to 6 carbon atoms, preferably from 1 to 3 carbon atoms. Methyl, ethyl propyl and isopropyl groups are especially preferred.
By the term xe2x80x9calicyclicxe2x80x9d it should be understood to include non-aromatic carbocyclic or heterocyclic ring systems with 3 to 20 carbon atoms.
The group A is preferably an optionally substituted aromatic group. It is also preferred that when the group A is optionally substituted by an alkyl group, one or more of the alkyl xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94 and xe2x80x94CHxe2x95x90CHxe2x80x94.
It is especially preferred that A is selected from the group selected from 1,2,5-benzenetriyl, 1,3,5-benzenetriyl and 1,3,4,5-benzenetetrayl, which are optionally substituted by one or more fluorine atoms. The group B4 preferably occupies position 1 of the especially preferred group A.
It is preferred that when n1+n2=2 and n3=0, A represents xe2x80x94CR1xe2x80x94 or an optionally substituted aromatic or alicyclic group. Alternatively, when n1=3 and n2+n3=0, A represents an optionally substituted aromatic or alicyclic group only.
The groups P1, P2 and P3 can be photoisomensed or photodimerised on exposure to UV or laser light. The groups P1 to P3 preferably undergo photocyclisation reactions. The groups P1 to P3 are preferably represented by the general formulae IIIa and IIIb: 
wherein the broken line indicates the point of linkage to S3 and wherein:
D represents pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, 1,4- or 2,6-naphthylene; a phenylene group, which is optionally substituted by a group selected from fluorine, chlorine cyano; or a C1-18 cyclic, straight-chain or branched alkyl residue, which is optionally substituted by a single cyano group or by one or more halogen groups and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Si(CH3)2xe2x80x94Oxe2x80x94Si(CH3)2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94, wherein R1 is as defined above;
E represents xe2x80x94OR3, xe2x80x94NR4R5 or an oxygen atom, which defines together with the ring D a coumarin unit, wherein R3, R4 and R5 are selected from hydrogen and a C1-18 cyclic, straight-chain or branched alkyl residue, which is optionally substituted by one or more halogen atoms and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94 and xe2x80x94CHxe2x95x90CHxe2x80x94, or R4 and R5 together form a C5-8 alicyclic ring;
X, Y each independently represent hydrogen, fluorine, chlorine, cyano or a C1-12 alkyl group, which is optionally substituted by fluorine and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94 and xe2x80x94CHxe2x95x90CHxe2x80x94;
R2 represents hydrogen or a C1-18 straight-chain or branched alkyl residue, which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are independently optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Si(CH3)2xe2x80x94Oxe2x80x94Si(CH3)2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94, wherein R1 is as defined above.
It is preferred that the groups X and Y represent hydrogen.
It is also preferred that the group D is selected from pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-thiophenylene, 2,5-furanylene, 1,4- or 2,6-naphthylene and a phenylene group, which is optionally substituted by a C1-12 cyclic, straight-chain or branched alkyl residue, which alkyl group is optionally substituted by one or more halogen groups and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are independently optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94 and xe2x80x94Cxe2x89xa1Cxe2x80x94.
It is especially preferred that D is selected from pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,5-furanylene, 1,4- or 2,6-naphthylene and phenylene, which is optionally substituted by a C1-6 straight-chain or branched alkyl residue, which alkyl group is optionally substituted by one or more fluorine atoms, and wherein one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are independently optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94 and xe2x80x94CHxe2x95x90CHxe2x80x94.
By the term xe2x80x9cphenylenexe2x80x9d it should be understood to include 1,2-, 1,3- or 1,4-phenylene, which is optionally substitutes. It is preferred that the phenylene group is either a 1,3- or a 1,4-phenylene, 1,4-phenylene groups are especially preferred.
Preferred groups E are selected from xe2x80x94OR3 and xe2x80x94NR4R5, wherein R3 and R4 represent a C1-18 cyclic, straight-chain or branched alkyl residue, which is optionally substituted by one or more halogen atoms, and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are independently optionally replaced by xe2x80x94Oxe2x80x94 or xe2x80x94CHxe2x95x90CHxe2x80x94, wherein R5 is selected from a hydrogen atom or a C1-18 cyclic, straight-chain or branched alkyl residue, which is optionally substituted by one or more halogen groups and which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are optionally independently replaced by xe2x80x94Oxe2x80x94 or xe2x80x94CHxe2x95x90CHxe2x80x94, or R4 and R5 together to form a C5-8 alicyclic ring.
It is especially preferred that E is selected from the group comprising xe2x80x94OR3 or xe2x80x94NHR4, wherein R3 and R4 represent a C1-18 cyclic, straight-chain or branched alkyl residue which is optionally substituted by one or more fluorine atoms and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are independently optionally replaced xe2x80x94Oxe2x80x94.
Preferred groups B1 to B4 are groups of formula II where n4+n5xe2x89xa61.
It is preferred that each of the groups C1 and C2 comprising the groups B1 to B4 are selected from cyclohexane-1,4-diyl, pyrimidine-2,5-diyl, pyrdine-2,5-diyl, 1,4- or 2,6-naphthylene and phenylene, which is optionally substituted by one or more groups selected from fluorine, chlorine, cyano and a C1-12 cyclic, straight-chain or branched alkyl residue, which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent allyl xe2x80x94CH2xe2x80x94 groups are optionally independently replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94.
It is especially preferred that the groups C1 and C2 are selected from cyclohexane-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, 2,6-naphthylene and phenylene, which is optionally substituted by one or more fluorine atoms or a C1-8 straight-chain or branched alkyl residue, which is optionally substituted by one or more fluorine atoms, and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups arm independently optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94 and xe2x80x94CHxe2x95x90CHxe2x80x94.
It is preferred that the groups S1 to S3 are selected from a single covalent bond, xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94 and a straight-chain or branched alkylene group, which is optionally substituted by one or more groups selected from fluorine, chlorine and cyano and in which two or three non-adjacent alkylene xe2x80x94CH2xe2x80x94 group are independently optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94NR2xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94 and xe2x80x94Si(CH3)2xe2x80x94Oxe2x80x94Si(CH3)2xe2x80x94, wherein R1 is as defined above and with the proviso that firstly, the total number of chain carbon atoms in the alkylene group does not exceed 24 and secondly, when the repeating monomer unit M is linked to B4 via a nitrogen atom or a oxygen atom S1, S2 and S3 are not xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 or xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94.
It is more preferred that S1 to S3 are selected from xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rNR1xe2x80x94COxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94NR2xe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COOxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94 and xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, wherein R1 is as defined above, r and s each represent an integer from 1 to 20, preferably from 2 to 12, and r+sxe2x89xa621, preferably xe2x89xa615.
By the terms xe2x80x94(CH2)rxe2x80x94 and xe2x80x94(CH2)sxe2x80x94 it should be understood to include straight-chain or branched alkylene groupings containing r or s carbon atoms respectively. Optional substituents include alkyl, aryl, cycloalkyl, amino, cyano, epoxy, halogen, hydroxy, nitro and oxo.
It is especially preferred that S1 to S3 are selected from xe2x80x94(CH2)rxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94NHxe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94O(CH2)rxe2x80x94COxe2x80x94NHxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94NHxe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94CH2)rxe2x80x94NHxe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94O, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94NHxe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, wherein r and s each represent an integer from 2 to 12 and r+sxe2x89xa615.
Examples of preferred the preferred groups S1 to S3 include 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,10-decylene, 1,11-undecylene, 1,12-dodecylene, 3-methyl-1,4-butylene, 3-propyleneoxy, 3-propyleneoxycarbonyl, 2-ethylenecarbonyloxy, 4-butyleneoxy, 4-butyleneoxycarbonyl, 3propylenecarbonyloxy, 5-pentyleneoxy, 5-pentyleneoxycarbonyl, 4-butylenecarbonyloxy, 6-hexyleneoxy, 6-hexyleneoxycarbonyl, 5-pentylenecarbonyloxy, 7-heptyleneoxy, 7-heptyleneoxycarbonyl, 6-hexylenecarbonyloxy, 8-octyleneoxy, 8-octyleneoxycarbonyl, 7-heptylenecarbonyloxy, 9-nonyleneoxy, 9-nonyleneoxycarbonyl, 8-octylenecarbonyloxy, 10decyleneoxy, 10-decyleneoxycarbonyl, 9-nonylenecarbonyloxy, 11-undecylencoxy, 11-undecyleneoxycarbonyl, 10-decylenecaonyloxy, 12-dodecyleneoxy, 12-dodecyleneoxycarbonyl, 11-undecylenecarbonyloxy, 3-propyleneiminocarbonyl, 4-butyleneiminocarbonyl, 5-pentyleneiminocarbonyl, 6-hexyleneiminocarbonyl, 7-heptyleneiminocarbonyl, 8-octyleneiminocarbonyl, 9-nonyleneimiocarbonyl, 10-decyleneiminocarbonyl, 11-undecyleneiminocarbonyl, 12dodecyleneiminocarbonyl, 2-ethylenecarbonylumno, 3-propylenecarbonylimino, 4-butylenecarbonylimino, 5-pentylenecarbonylimino, 6-hexylenecarbonylimino, 7-heptylenecarbonylimino, 8-octylenecarbonylimino, 9-nonylenecarbonylinino, 10-decylenecarbonylimino, 11-undecylenecarbonylimino, 6-(3-propyleneimiocarbonyloxy)hexylene, 6-(3-propyleneoxy)hexylene, 6-(3-propyleneoxy)hexyleneoxy, 6(3-propyleneminocarbonyloxy)hexyleneoxy, 6-(3-propyleneiminocarbonyl)hexyl, 6-(3-propyleneiminocarbonyl)hexyloxy, 1,2-ethylenedioxy, 1,3-propylenedioxy, 1,4-butylenedioxy, 1,5-pentylenedioxy, 1,6-hexylenedioxy, 1,7-heptylenedioxy, 1,8-octylenedioxy, 1,9-nonylenedioxy, 1,10-decylenedioxy, 1,11-undecylenedioxy, 1,12-dodecylenedioxy and the like.
It is preferred that the unit of formula (I) comprises at least 50% of the monomer building blocks, which form the main chain of a photoactive polymer. It is especially preferred that the unit of formula (I) comprises at least 70% of the monomer building blocks forming the photoactive polymer.
The repeating monomer unit M represents part of a homopolymer or a co-polymer. It is preferred that M forms part of a co-polymer. By the term xe2x80x9ccopolymerxe2x80x9d it is to be understood to include statistical copolymers.
The repeating monomer units M are preferably selected from acrylate; methacrylate; 2-chloroacrylate; 2-phenylacrylate; acrylamide, methacrylamide, 2-chloroarylamide and 2-phenylacrylamide, the nitrogen atom of which is optionally substituted by a lower alkyl group; vinyl ether; vinyl ester, a styrene derivative; siloxane; imide; amic acid; amic acid esters; amidimide; maleic acid derivatives and fumaric acid derivatives.
It is more preferred that the repeating monomer unit M is selected from acrylate; methacrylate; acrylamide and methacrylamide the nitrogen atom of which is optionally substituted by a lower alkyl group; vinyl ether, vinyl ester, a styrene derivative, imide, amic acid, amic acid esters and amidimide.
It is especially preferred that the repeating monomer unit M is selected from acrylate, methacrylate, a styrene derivative, imide, amic acid, amic acid ester, and amidimide.
When the monomer unit M is an imide group, it is preferably selected from structures of the general formulae VI, VII, VIII, IX, X and XI: 
wherein the broken line symbolises the linkage to B4 
T1 represents a tetravalent organic radical;
T2, T3 each independently represent a trivalent aromatic or alicyclic group which is optionally substituted by a group selected from fluorine, chlorine, cyano and a C1-18 cyclic, straight-chain or branched alkyl residue, which is optionally substituted by one or more halogen groups and in which one or more non-adjacent alkyl xe2x80x94CH2xe2x80x94 groups are independently optionally replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94 and xe2x80x94Cxe2x89xa1Cxe2x80x94,
S4 to S8 are each independently selected from a single covalent bond and a C1-24 straight-chain or branched alkylene residue, which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent alkylene xe2x80x94CH2xe2x80x94 groups are, independently, optionally be replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94CO, xe2x80x94Si(CH3)2xe2x80x94Oxe2x80x94Si(CH3)2xe2x80x94, xe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94Cxe2x89xa1Cxe2x80x94 and xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94, wherein R1 is as defined above;
J is selected from the group comprising a nitrogen atom, a group xe2x80x94CR1xe2x80x94 and an aromatic or alicyclic divalent, trivalent or tetravalent group, which is optionally substituted by one or more groups selected from fluoro, chloro, cyano and a C1-18 cyclic, straight-chain or branched alkyl residue which is optionally substituted by a single cyano group or by one or more halogen atoms and in which one or more non-adjacent xe2x80x94CH2xe2x80x94 groups are, independently, optionally, replaced by a group selected from xe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94 and xe2x80x94Cxe2x89xa1Cxe2x80x94 wherein R1 is as defined above;
K represents an aliphatic, alicyclic or aromatic divalent radical; and
G represents a hydrogen atom or a monovalent organic group.
By the term xe2x80x9caliphaticxe2x80x9d it should be understood to include saturated and unsaturated, straight-chain and branched alkyl groups, which may be optionally substituted and in which one or more non-adjacent xe2x80x94CH2xe2x80x94 groups are replaced by one or more heteroatoms. Optional substituents include alkyl, aryl, cycloalkyl, amino, cyano, epoxy, halogen, hydroxy, nitro and oxo. Examples of heteroatoms that can replace the one or more xe2x80x94CH2xe2x80x94 groups include nitrogen, oxygen and sulfur. Replacement nitrogen atoms may be further substituted with groups such as alkyl, aryl and cycloalkyl.
The tetravalent organic radical T1 is preferably derived from an aliphatic, alicyclic or aromatic tetracarboxylic acid dianhydride. Alicyclic or aliphatic tetracarboxylic acid anhydrides are preferably selected from butanetetracarboxylic acid dianhydride, ethylenemaleic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbornylacetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic acid dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid dianhydride and 1,8-dimethylbicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride.
Aromatic tetracarboxylic acid dianhydrides are preferably selected from pyromellitic acid dianhydride, 3,3xe2x80x2,4,4xe2x80x2-benzophenonetetracarboxylic acid dianhydride, 4,4xe2x80x2-oxydiphthalic acid dianhydride, 3,3xe2x80x2,4,4xe2x80x2-diphenylsulfonetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3xe2x80x2,4,4xe2x80x2-dimethyldiphenylsilanetetracarboxylic acid dianhydride, 3,3xe2x80x2,4,4xe2x80x2-tetraphenylsilanetetracarboxylic acid dianhydride, 1,2,3,4-furantetracarboxylic acid dianhydride, 4,4xe2x80x2-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4xe2x80x2-bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride, 4,4xe2x80x2-bis(3,4dicarboxyphenoxy)diphenylpropane dianhydride, 3,3xe2x80x2,4,4xe2x80x2-biphenyltetracarboxylic acid dianhydride, ethylene glycol bis(trimellitic acid) dianhydride, 4,4xe2x80x2-(1,4-phenylene)bisphthalic acid) dianhydride, 4,4xe2x80x2-(1,3-phenylene)bis(phthalic acid) dianhydride, 4,4xe2x80x2-(hexafluoroisopropylidene)diphthalic acid dianhydride, 4,4xe2x80x2-oxydi(1,4-phenylene)bis(phthalic acid) dianhydride and 4,4xe2x80x2-methylenedi(1,4-phenylene)bis(phthalic acid) dianhydride.
It is especially preferred that the tetracarboxylic acid dianhydrides used to form the tetravalent organic radical T1 are selected from 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, 4-(2,5dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid dianhydride, 4,4xe2x80x2-(hexafluoroisopropylidene)diphthalic acid dianhydride and bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride.
Each of the groups T2 and T3 can be derived from an aliphatic, alicyclic or aromatic dicarboxylic acid anhydride.
The groups T2 and T3 are preferably trivalent aromatic or alicyclic groups, the three valencies of which are distributed between three different carbon atoms, with the proviso that two of the valencies are located at adjacent carbon atoms. It is especially preferred that the groups T2 and T3 are trivalent benzene derivatives.
The group S4 is preferably selected from a single covalent bond, xe2x80x94(CH2)rxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94(CH2)r1xe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)s, xe2x80x94(CH2)rxe2x80x94O(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94OCxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94COxe2x80x94Oxe2x80x94 and xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94COxe2x80x94, wherein R1 is as defined herein above; r and s each represent an integer from 1 to 20; and r+sxe2x89xa621. It is more preferred that r and s each represent an integer from 2 to 12. It is especially preferred that r+sxe2x89xa615.
Examples of preferred groups S4 include 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,1-decylene, 1,11-undecylene, 1,12-dodecylene, 3-methyl-1,4-butylene, 3-propyleneoxy, 3-propyleneoxycarbonyl, 2-ethylenecarbonyloxy, 4-butyleneoxy, 4-butyleneoxycarbonyl, 3-propylenecarbonyloxy, 5-pentyleneoxy, 5-pentyleneoxycarbonyl, 4-butylenecarbonyloxy, 6-hexyleneoxy, 6-hexyleneoxycarbonyl, 5-pentylenecarbonyloxy, 7-heptyleneoxy, 7-heptyleneoxycarbonyl, 6-hexylenecarbonyloxy, 8-octyleneoxy, 8-octyleneoxycarbonyl, 7-heptylenecarbonyloxy, 9-nonyleneoxy, 9-nonyleneoxycarbonyl, 8-octylenecarbonyloxy, 10-decyleneoxy, 10-decyleneoxycarbonyl, 9-nonylenecarbonyloxy, 11-undecyleneoxy, 11-undecyleneoxycarbonyl, 10-decylenecarbonyloxy, 12-dodecyleneoxy, 12-dodecyleneoxycarbonyl, 11-undecylenecarbonyloxy, 3-propyleneocarbonyl, 4-butyleiminocarbonyl, 5-pentyleneiminocarbonyl, 6-hexyleneiminocarbonyl, 7-heptyleneiminocarbonyl, 8-octyleneiminocarbonyl, 9-nonylenemocarbonyl, 10-decyleneiminocarbonyl, 11-undecyleneiminocarbonyl, 12-dodecyleneiminocarbonyl, 2-ethylenecarbonylimino, 3-propylenecarbonylimino, 4-butylenecarbonylimino, 5-pentylenecarbonylimino, 6-hexylenecarbonylimino, 7-heptylenecarbonylimino, 8-octylenecarbonylimino, 9-nonylemecarbonylimino, 10-decylenecarbonylimino, 11-undecylenecarbonylimino, 6-(3-propyleneiminocarbonyloxy)hexylene, 6-(3-propyleneoxy)hexylene, 6-(3-propyleneoxy)hexyleneoxy, 6-(3-propyleneiminocarbonyloxy)hexyleneoxy, 6-(3-propyleneiminocarbonyl)hexylene, 6-(3-propyleneiminocarbonyl)hexyleneoxy and the like.
The groups S5 and S8 are preferably selected from a single bond, xe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)s, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)s, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)s, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)s, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94 and xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, wherein R1 is defined as herein above; r and s each represent an integer from 1 to 20; and r+sxe2x89xa621. It is more preferred that r and s each represent an integer from 2 to 12. It is further preferred that r+sxe2x89xa615.
Examples of preferred groups S5 and S8 include 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,10-decylene, 1,11-undecylene, 1,12-dodecylene, 3-methyl-1,4-butylene, 2-oxyethylene, 3-oxypropylene, 4-oxybutylene, 5-oxypentylene, 6-oxyhexylene, 7-oxyheptylene, 8-oxyoctylene, 9-oxynonylene, 10-oxydecylene, 11-oxyundecylene, 12-oxydodecylene, 2-(oxycarbonyl)ethylene, 3-(oxycarbonyl)propylene, 4-(oxycarbonyl)butylene, 5-oxycarbonyl)pentylene, 6-(oxycarbonyl)hexylene, 7-(oxycarbonyl)heptylene, 5-(oxycarbonyloctylene, 9-(oxycarbonyl)nonylene, 10-(oxycarbonyl)decylene, 11-(oxycarbonyl)undecylene, 12-(oxycarbonyl)dodecylene, 2-(carbonyloxy)ethylene, 3carbonyloxy)propylene, 4-(carbonyloxy)butylene, 5-(carbonyloxypentylene, 6-(carbonyloxy)hexylene, 7carbonyloxy)heptylene, 8-(carbonyloxy)octylene, 9-(carbonyloxy)nonylene, 10-(carbonyloxy)decylene, 11-(carbonyloxy)undecylene, 12-(carbonyloxy)dodecylene, 2-(carbonylimino)ethylene, 3-(carbonylimino)propylene, 4(carbonylimino)butylene, 5-(carbonylimino)pentylene, 6-(carbonylimno)hexylene, 7-(carbonylimino)heptylene, 8-(carbonylimo)octylene, 9-(carbonylimino)nonylene, 10-(carbonylimino)decylene, 11-(carbonylimino)undecylene, 12-(carbonylimino)dodecylene, 2-iminoethylene, 11-iminopropylene, 4-iminobutylene, 5-iminopentylene, 6-iminohexylene, 7-iminoheptylene, 8-iminooctylene, 9-iminononylene, 10-iminodecylene, 11-iminoundecylene, 12-iminododecylene, 2-imiocarbonylethylene, 3-iminocarbonylpropylene, 3-iminocarbonylbutylene, 5-iminocarbonylpentylene, 6-iminocarbonylhexylene, 7-iminocarbonylheptylene, 8-iminocarbonyloctylene, 9-iminocarbonylnonylene, 10-iminocarbonyldecylene, 11-iminocarbonylundecylene, 12-iminocarbonyldodecylene, 2-(2-ethyleneoxy)ethylene, 2-(3-propyleneoxy)ethylene, 6-(4butyleneoxy)hexylene, 2-(2-ethyleneiminocarbonyl)ethylene, 2-(3-propyleneiminocarbonyl)ethylene, 6-(4-butyleneiminocarbonyl)hexylene, 6-(3-propyleneiminocarbonyloxy)hexylene, 6-(3-propyleneiminocarbonyl)hexylene and the like.
The groups S6 and S7 are preferably selected from a single bond, xe2x80x94(CH2)rxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94, xe2x80x94NR1xe2x80x94COxe2x80x94(CH2)r, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94NR1xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94COxe2x80x94NR1(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94COxe2x80x94NR1xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94CO(CH2)rxe2x80x94COxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94CHxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94COxe2x80x94NR1xe2x80x94, xe2x80x94Oxe2x80x94COxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94Oxe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)s, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94Oxe2x80x94(CH2)rxe2x80x94NR1xe2x80x94COxe2x80x94Oxe2x80x94(CH2)sxe2x80x94Oxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94Oxe2x80x94(CH2)sxe2x80x94, xe2x80x94COxe2x80x94Oxe2x80x94(CH2)rxe2x80x94O(CH2)sxe2x80x94Oxe2x80x94, wherein R1 is defined as herein above; r and s each represent an integer from 1 to 20; and +sxe2x89xa621. It is more preferred that r and s each represent an integer from 2 to 12. It is especially preferred that r+s xe2x89xa615.
Examples of preferred groups S6 and S7 include 1,2-ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,9-nonylene, 1,10-decylene, 1,11-undecylene, 1,12-dodecylene, 3-methyl-1,4-butylene, 3-propyleneoxy, 3-propyleneoxycarbonyl, 2-ethylenecarbonyloxy, 4-butyleneoxy, 4-butyleneoxycarbonyl, 3-propylenecarbonyloxy, 5-pentyleneoxy, 5-pentyleneoxycarbonyl, 4-butylenecarbonyloxy, 6-hexyleneoxy, 6-hexyleneoxycarbonyl, 5-pentylenecarbonyloxy, 7-heptyleneoxy, 7-heptyleneoxycarbonyl, 6-hexylenecarbonyloxy, 8-octyleneoxy, 8-octyleneoxycarbonyl, 7-heptylenecarbonyloxy, 9-nonyleneoxy, 9-nonyleneoxycarbonyl, 9-octylenecarbonyloxy, 10-decyleneoxy, 10-decyleneoxycarbonyl, 9-nonylenecarbonyloxy, 11-undecyleneoxy, 11-undecyleneoxycarbony, 10-decylenecarbonyloxy, 12-dodecyleneoxy, 12-dodecyleneoxycarbonyl, 11-undecylenecarbonyloxy, 3-propyleneiminocarbonyl, 4-butyleneiminocarbonyl, 5-pentyleneiminocarbonyl, 6-hexyleneiminocarbonyl, 7-heptyleneiminocarbonyl, 8-octyleneiminocarbonyl, 9-nonyleneiminocarbonyl, 10-decyleneiminocarbonyl, 11-undecyleneiminocarbonyl, 12-dodecyleneiminocarbonyl, 2-ethylenecarbonylimino, 3-propylenecarbonylimino, 4-butylenecarbonylimino, 5-pentylenecarbonylimino, 6-hexylenecarbonylimino, 7-heptylenecarbonylimino, 8-octylenecarbonylimino, 9-nonylemecarbonylimino, 10-decylenecarbonylimino, 11-undecylenecarbonylimino, 6-(3-propyleneiminocarbonyloxy)hexylene, 6(3-propyleneoxy)hexylene, 6-(3-propyleneoxy)hexyleneoxy, 6-(3-propyleneiminocarbonyloxy)hexyleneoxy, 6-(3-propyleneiminocarbonyl)hexyl, 6-(3-propyleneiminocarbonyl)hexyloxy, 1,2-ethylenedioxy, 1,3-propylenedioxy, 1,4-butylenedioxy, 1,5-pentylenedioxy, 1,6-hexylenedioxy, 1,7-heptylenedioxy, 1,8-octylenedioxy, 1,9-nonylenedioxy, 1,10-decylenedioxy, 1,11-undecylenedioxy, 1,12-dodecylenedioxy and the like.
The aliphatic, alicyclic or aromatic divalent radical K is derivable from aliphatc, alicyclic or aromatic diamines by formal removal of the amino groups. Examples of aliphatic or alicyclic diamines from which the radical K can be derived include ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, 1,5-pentylenediamine, 1,6-hexylenediamine, 1,7-heptylenediamine, 1,8-octylenediamine, 1,9-nonylenediamine, 1,10decylenediamine, 1,11-undecylenediamine, 1,12-dodecylenediamie, xcex1,xcex1xe2x80x2-diamino-m-xylene, xcex1,xcex1xe2x80x2-diamino-p-xylene, (5-amino-2,2,4-trimethylcyclopentyl)methylamine, 1,2-diaminocyclohexane, 4,4xe2x80x2-diaminodicyclohexylmethane, 1,3-bis(methylamino)cyclohexane, and 4,9-dioxadodecane-1,12-diamine.
Examples of aromatic diamines from which the radical K can be derived include 3,5-diaminobenzoic acid methyl ester, 3,5-diaminobenzoic acid hexyl ester, 3,5-diaminobenzoic acid dodecyl ester, 3,5-diaminobenzoic acid isopropyl ester, 4,4xe2x80x2-methylenedianiline, 4,4xe2x80x2-ethylenedianiline, 4,4xe2x80x2-diamino-3,3xe2x80x2-dimethyldiphenylmethane, 3,3xe2x80x2,5,5xe2x80x2-tetramethylbenzidine, 4,4xe2x80x2-diaminodiphenyl sulfone, 4,4xe2x80x2-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3xe2x80x2-dimethyl-4,4xe2x80x2-diaminobiphenyl, 3,4xe2x80x2-diaminodiphenyl ether, 3,3xe2x80x2-diaminobenzophenone, 4,4xe2x80x2-diaminobenzophenone, 4,4xe2x80x2-diamino-2,2xe2x80x2-dimethylbibenzyl, 2,2-bis[4(4aminophenoxy)phenyl]sulfone, 1,4-bis(4aminophenoxy)benzene, 1,3-bis(4aminophenoxy)benene, 1,3-bis(3-aminophenoxy)benzene, 2,7-diaminofluorene, 9,9-bis(4-aminophenyl)fluorene, 4,4xe2x80x2-methylenebis(2-chloroaniline), 4,4-bis(4amiophenoxy)biphenyl, 2,2xe2x80x2,5,5xe2x80x2-tetrachloro-4,4xe2x80x2-2,2xe2x80x2-dichloro-4,4xe2x80x2-diamino-5,5xe2x80x2- diethoxybiphenyl, 3,3xe2x80x2-diethoxy-4,4xe2x80x2-diaminobiphenyl 4,4xe2x80x2-(1,4-phenyleneisopropylidene)bisenile, 4,4xe2x80x2-(1,3-phenyleneisopropylidene)bisaniline, 2,2-bis[4(4-aminophenoxy)phenyl]-propane, 2,2-bis[3-(4aminophenoxyphenyl]hexafluoropropane, 2,2-bis[3-amino-4-methylphenyl]hexafluoropropane, 2,2-bis(4aminophenyl)hexafluoropropane, 2,2xe2x80x2-bis[4(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane, 4,4xe2x80x2-diamino-2,2xe2x80x2-bis(trifluoromethyl)biphenyl, and 4,4xe2x80x2-bis[(4-amino-2-trifluoromethyl)phenoxy]-2,3,5,6,2xe2x80x2,3xe2x80x2,5xe2x80x2,6xe2x80x2-octafluorobiphenyl.
The group J may be divalent, trivalent or tetravalent. When J is divalent, it serves to link the groups S4 and S5, S6 and S7 and S8 and N respectively of the groups VI to XI, It will be appreciated that when J is a divalent group, the monomer unit of which it forms a part is not linked to a side chain group B4. When J is a trivalent or a tetravalent group, it serves to link the monomer unit M, of which it forms a part, to one or two side chain groups B4 respectively. It is preferred that the photoactive polymer comprises less than 75%, of monomer units including a divalent group J, preferably less than 50% and especially less than 30%. Monomer units M comprising a trivalent group J are preferred.
The building blocks of the formulae VII, IX and XI are amic acid groupings or amic acid ester groupings (i.e. carboxamide-carboxylic acid groupings or carboxamide-carboxylic acid ester groupings) which on the one hand may occur as a result of incomplete imidisation in the polyimide chain. On the other hand, polymers that consist only of building blocks of formulae VII, IX or XI, that is to say polyamic acids or polyamic acid esters, are important precursors for the preparation of the polyimides according to the invention and are also included in the present invention. Of those polymers which contain groups of formulae VII, IX or XI, preference is given to those in which G is hydrogen, that is to say those which consist exclusively of, or contain some, polyamic acid groups.
The polymers of the invention may be prepared using methods that are known to a person skilled in the art and a second aspect of the invention provides a method of preparing a compound of formula (I) as defined above.
The polymers of formula I, with acrylate, methacrylate and styrene derivative as repeating monomer unit, can be prepared in principle according to two different processes. In addition to the direct polymerisation of pre-finished monomers there exists the possibility of polymer-analogous reaction of reactive photoactive all derivatives with functional polymers.
For the direct polymerisation, the monomers and the comonomers are firstly prepared separately from the individual components. The formation of the polymers is subsequently effected in a manner known per se under the influence of UV radiation or heat or by the action of radical or ionic catalysts. Potassium peroxodisulfate, dibenzoyl peroxide, azobisisobutyronitrile or di-tert-butyl peroxide are examples of radical initiators. Ionic catalysts are alkali-organic compounds such as phenyllithium or naphthylsodium or Lewis acids such as BF3, AlCl3, SnCl3 or TiCl4. The monomers can be polymerised in solution, suspension, emulsion or substance.
In the second process a polymer of formula I can also be produced in a polymer-analogous reaction from a pre-finished functional polymer and a suitable functionalised photoactive derivative. Many known processes such as, for example, esterification, trans-esterification, amidation or the etherification are suitable for polymer-analogous reactions.
Acrylate, methacrylate and styrene polymers typically have a molecular weight MW of from 1 000 to 5 000 000, preferably from 5 000 to 2 000 000, and especially from 10 000 to 1 000 000.
Polyamic acids and polyimides of the present invention may be prepared in accordance with known methods, such as those described in Plast. Eng. 36 (1996) (Polyimides, fundamentals and applications).
For example, the polycondensation reaction for the preparation of the polyamic acids is carried out in solution in a polar aprotic organic solvent, such as xcex3-butyrolactone, N,N-dimethylacetamide, N-methylpyrrolidone or N,N-dimethylformamide. In most cases equimolar amounts of the dianhydride and the diamine are used, that is to say one amino group per anhydride group. If it is desired to stabilise the molecular weight of the polymer, it is possible for that purpose to add an excess or a less-than-stoichiometric amount of one of the two components or to add a monofunctional compound in the form of a dicarboxylic acid monoanhydride or in the form of a monoamine. Examples of such monofunctional compounds are maleic acid anhydride, phthalic acid anhydride, aniline and so on. The reaction is carried out preferably at a temperature of less than 100xc2x0 C.
The cyclisation of the polyamic acids to form the polyimides can be carried out by heating, that is to say by condensation with removal of water or by other imidisation reactions with reagents. When carried out purely thermally, the imidisation of the polyamic acids is not always complete, that is to say the resulting polyimides may still contain proportions of polyanic acid. The imidisation reactions are generally carried out at a temperature of from 60 to 250xc2x0 C., but preferably at less than 200xc2x0 C. In order to achieve imidisation at rather lower temperatures there are additionally mixed into the reaction mixture reagents that facilitate the removal of water. Such reagents are, for example, mixtures consisting of acid anhydrides, such as acetic acid anhydride, propionic acid anhydride, phthalic acid anhydride, trifluoroacetic acid anhydride, and tertiary amines, such as triethylaine, trimethylamine, tributylamine, pyridine, N,N-dimethylaniline, lutidine, collidine etc., The amount of reagents used in that case is preferably at least two equivalents of amine and four equivalents of acid anhydride per equivalent of polyamic acid to be condensed.
The imidisation reaction can be carried out before or alternatively only after application to a support. The latter variant is preferred especially when the polyimide in question has poor solubility in the customary solvents.
The polyamic acids and the polyimides of the present invention have an intrinsic viscosity preferably in range of 0.05 to 10 dL/g, more preferably 0.05 to 5 dL/g. Herein, the intrinsic viscosity (xcex7inh=ln xcex7rel/C) is determined by measuring a solution containing a polymer in a concentration of 0.5 g/100 ml for its viscosity at 30xc2x0 C. using N-methyl-2-pyrrolidone as solvent.
The polyamic acid chains or polyimide chains of the present invention preferably contain from 2 to 2000 monomer units, especially from 3 to 200.
Additives such as silane-containing compounds and epoxy-containing crosslinking agents may be added to the polymers of the invention in order to improve the adhesion of the polymer to a substrate. Suitable silane-containing compounds are described in Plast. Eng. 36 (1996) (Polyimides, fundamentals and applications). Suitable epoxy-containing crosslinking agents include 4,4xe2x80x2-methylenebis-(N,N-diglycidylaniline), timethylolpropane triglycidyl ether, benzene-1,2,4,5-tetracarboxylic acid 1,2:4,5-N,Nxe2x80x2-diglycidyldiimide, polyethylene glycol diglycidyl ether, N,N-diglycidylcyclohexylamine and the like.
Further additives such a photosensitiser, a photoradical generator and/or a cationic photoinitiator may also be added to the polymers of the invention. Suitable photoactive additives include 2,2-dimethoxyphenylethanone, a mixture of diphenylmethanone and N,N-dimethylbenzenamine or ethyl-4-(dimethylamino)benzoate, xanthone, thioxanthone, Irgacure(trademark) 184, 369, 500, 651 and 907 (Ciba), Michler""s ketone, triarl sulfonium salt and the like.
The polymers according to the invention may be used alone or in combination with other polymers, oligomers, monomers, photoactive polymers, photoactive oligomers and/or photoactive monomers, depending up on the application to which the polymer layer is to be put. It will therefore be appreciated that by varying the composition of the polymer layer it is possible to control properties such as an induced pretilt angle, good surface wetting, high voltage holding ratio, a specific anchoring energy etc.
Polymer layers may be readily prepared from the polymers of the present invention and a third aspect of the invention provides a polymer layer comprising a polymer according to the present invention in a cross-linked form. The polymer layer is preferably prepared by applying one or more polymers according to the invention to a support and, after any imidisation step which may be necessary, crosslinkig the polymer or polymer mixture by irradiation with linearly polarised light. It is possible to vary the direction of orientation and the tilt angle within the polymer layer by controlling the direction of irradiation of the linearly polarised light. It will be appreciated that by selectively irradiating specific regions of the polymer layer it is possible to align very specific regions of the layer and provide layers with a defined angle of tilt. This orientation and tilt is retained in the polymer layer by the process of cross-linking.
It will be appreciated that the polymer layers of the present invention can also be used as orientation layers for liquid crystals and a preferred embodiment of the third aspect of the invention provides an orientation layer comprising one or more polymers according to the invention in a cross-linked form. Such orientation layers can be used in the manufacture of optical constructional elements, preferably in the production of hybrid layer elements.
The orientation layers are suitably prepared from a solution of the polymer material. The polymer solution is applied to a support optionally coated with an electrode (for example a glass plate coated with indium-tin oxide (ITO)) by a spin coating process, to produce homogeneous layers of 0.05 to 50 xcexcm thickness. The resulting layer is imidised, if required, and may then be selectively orientated by irradiation with a high-pressure mercury vapour lamp, a xenon lamp or a pulsed UV laser, using a polariser and optionally a mask for creating images of structures. The irradiation time is dependent upon the output of the individual lamps and can vary from a few seconds to several hours. The cross-linking reaction can also be carried out by irradiation using filters that, for example, only allow the radiation suitable for the cross-linking reaction to pass through.
It will be appreciated that the polymer layers of the invention may be used in the production of optical or electro-optical devices having at least one orientation layer as well as unstructured and structured optical elements and multi-layer systems. A further embodiment of the third aspect of the invention provides an optical or electro-optical device comprising one or more polymers according to the first aspect of the invention in cross-linked form. The electro-optical devices may comprise more than one layers. The or each of the orientation layers may contain one or more regions of different spatial orientation.
The invention will now be described with reference to the following non-limiting examples in which Tg represents the glass temperature, C represents the crystalline phase, N represents the nematic phase, I represents the isotropic phase, pdi represents the polydispersity index and p represents the number of repeating units in the polymer. Relative molecular weights were determined by gel permeation chromatography (GPC) at 35xc2x0 C. using THF as solvent with polystyrene added. Variations of these examples failing within the scope of the present invention will be apparent to a person skilled in the art.